Process and apparatus for the lowtemperature distillation of solid fuels



July 3, 1934. J, HERENG 1,964,878

PROCESS AND APPARATUS FOR THE LOW TEMPERATURE DISTILLATION OF SOLIDFUELS Filed May 28, 1931 4 Sheets-Sheet 1 July 3, 1934. J, A, HERENG1,964,878

PROCESS AND APPARATUS FOR THE LOW TEMPERATURE DISTILLATION 0F SOLIDFUELS Filed May 28, 1931 4 Sheets-Sheet 2 Fig.2

z wewfor T Has ATYORN c y 3, 1934- A. J. A. HERENG 1,964,873

PROCESS AND APPARATUS FOR THE LOW TEMPERATURE DISTILLATION OF SOLIDFUELS Filed May 28, 1931 4 Sheets-Sheet 3 ms arromvsy A. J. A. HERENGJuly 3, 1934. 1,964,878

PROCESS AND APPARATUS FOR THE LOW TEMPERATURE DISTILLATION 0F SOLIDFUELS Filed May 28, 1951 4 Sheets-Sheet 4 x rzvezziair 14/1EEDJE0Nmam/52am 8 Y H a 5 A T'To R H Y compact c Patented July 3, 19341,964,878 PATENT OFFICE PROCESS AND APPARATUS FOR THE LOW- TEEHPEBATUBEDISTILLATION F SOLID Alfred Jean Andre Hereng, Paris, France ApplicationMay I In 28, 1931, Serial No. 540,609

France May 30, 1930 '7 Claims. '(Cl. 202-9) The present inventionrelates the low-temperature distillation of solid fuels spread out in. asheet in a heated chamber, upon a horizontal I conveyor which ispermeable to gases, thelower' face of the said sheet being subjected toauction so as to draw through the layer of fuel the gaseous productsresulting from the distillation.

It has been shown by experience that the distillation of fuel does notalways take place in a uniform manner throughout the mass of the fuelunder treatment. The upper part of the traveling sheet of fuel vwillfirst distill and a crust of semi-coke will form, the permeability ofwhich depends on the agglomerating nature of the fuel.

' The distillation of the upper part of the mass may be delayed, or itcan only take place by superheating the fuel before it leaves thedistilling chamber.

The present invention relates to means and devices whereby all suchdrawbacks will be eliminated in whatever degree they may occur.

For this purpose, in accordance with the present invention, when thefuel has'passed through a part of its oursein the distilling chamber,the t of the completely distilled fuel formed at the upper part of thesheet of fuel is automatically broken up within the chamber. Preferably,this broken up layer is immediately removed from the distilling chamber.Thus the subjacent part of the fuel mass which is charged withsubstances adapted for distillation, and which is still permeable togases, islaid bare. The upper layer of this subjacent part is thendistilled in turn; it is broken up and removed a from the distillingchamber after the volatile substances it contains have been distilled,and it ,is converted into semi -coke. The same operation takes place 11times until the sheet of fuel 1 reaches the end of the distillingchamber. Only a thin horizontal layer of fuel adapted for distillationthroughout its whole mass will be left on the conveyor during the lastpart of its travel in the distilling chamber.

The chief advantages of my process are as foli lows:

1. Reduction of the time required for the distillation of a given massof fuel, this reduction being due to the fact that the fuel permeable tothe heating gases and to the gases of distillation, is brought intocontact with such gases in n+1 sections of the distilling chamber, orthroughout the length of said chamber, instead of a fraction of thislength,

2. Superheating as now employed to eflect the distillation ofthe' fuelthroughout the whole thickness of-J' the mass under treatment, is

3. The production of condensable resulting from distillation effected ata low and uniform temperature, since the fuel has not been superheatedat any point in the distilling chamber. g

4. An increase in the heating power of the resulting gas, by virtue ofthe large amount of methane in this gas, dueto the low temperature ofthe distillation. g

The present invention covers, in addition to the aforesaid proces andmeans, the use of said process and means in combination with theproccases and means specified in the applicant's prior application forpatent Serial No. 325,188.

The invention includes apparatus suitable for use in carrying out theprocess. This apparatus may include:

1. Rotary crust-breaking and removing devices or scrapers, which breakup the crust of agglom erated fuel formed in the upper part of the layerof fuel, and transport the broken pieces of the crust out of thedistilling chamber substantially at right angles to the direction oftravel of the endless conveyor. Each of the crust-removing devices orscrapers consists of helical paddles or blades mounted on acommon shaftmounted above the sheet of fuel and substantially at right angles to thelatter.

2. The combination with each crust-breaking and removing device of astop plate which is parallel to said shaft carrying the helical paddlesand is mounted above the distilled fuel and in front of the broken-upcrust of the distilled fuel, thus preventing such broken pieces frombeing transported by the endless conveyor, and assurin; the displacementof such pieces at right anglee to the direction of travel of the endlessconveyor.

3. A device for the vertical adjustment of each stop plate.

4. A leakless collecting chamber adapted to receive the partial massesof the semi-coke in the broken state as delivered by the said scrapers.The collecting chamber may be provided with the following devices:

(a) A hopper for the supply of an apparatus which is combined with thedistilling chamber.

(b) Or a general conveyor for all the semi-coke produced in thedistilling chamber.

(0) Or both of these devices. I

The accompanying drawings which are given by way of example and in nowise limit the scope of the invention diagrammatically illustrate thedistilling apparatus.

In these drawings:

Fig. 1 is a longitudinalsection through the distilling apparatus whichis provided with crus breaking and removing devices.

Fig. 2 is a section on line II--II of Fig. 1.

Fig. 3 is a partial longitudinal section showing an apparatus similar tothe one shown in Figure 1 and whose collecting chamber is provided witha conveyor delivering the semi-coke into a cleaning device.

Fig. 4 is a detail view in vertical cross section of part of adistilling apparatus comprising two chambers forming a pair, the sectionbeing taken on the longitudinal axis of an apparatus serving for thetransverse removal of the distilled fuel.

In these figures, the same reference numerals relate to like parts.

Referr ng to Figure l, l is the distilling chamber, which is providedwith the following elements: a hopper 2 for the supply of fine coal tobe distilled, a gate 3 for regulating the height of the layer of fuel 4in the distilling chamber; a movable endless grate 5 whose upper part 6serves to transport the fuel and also forms a support which is permeableto the gases of distillation; suction chests 7 used for the withdrawalof such gases and positioned below the grate; conduits 8 for the heatinggas issuing from a channel 9.

Above the layer 4 of the fuel spread on the upper part 6 of saidpermeable conveyor are situated rotary scrapers, two being employed inthe present case. Each scraper is placed across the path followed by thefuel through the distilling chamber; each scraper has a shaft (10*- forthe first and 10 for the second), and helical paddles (11- for the firstand 11 for the second). The paddles cut up the crust of the agglomeratedfuel, and at the same time they convey it across the chamber to alateral outlet (12 for the first scraper and 12 for the second). Eachscraper is combined with a stop plate (13 for the first and 13 for thesecond), adapted to arrest the agglomerated fuel which has moved pastthe pad-- dles. The lower edges (13* -14 of each stop plate are smoothor toothed. For coal which ag-- glomerates readily, the lower edge ofeach plate is toothed.

The lower end of each stop plate is at such height that thelayer of coalwhich comes into contact with the plate will consist of coal which iscompletely distilled, and hence this mass will be stopped. The crust 4which is formed in the first part of the distilling chamber 1 is notsuificiently permeable to the gases and its thickness increases with thedistance from its entrance into the chamber. This crust is broken up andremoved from the chamber by the scraper 10 -11'- and the stop plate 13.The part of the fuel which moves past this scraper and plate is alwaysin the state of fine coal and is hence permeable to the gases. This partof the fuel is thus laid bare and as it continues to travel through thedistilling chamber, a crust 4 will form thereon whose thicknessincreases down to the succeeding scraper 10 This scraper breaks up andremoves the crust 4', while the stop plate 13 arrests the parts of thiscrust which have escaped the action of the paddles 11 and pushes themback on the latter.

The part of the fuel which rests directly upon the movable grate willreach the end of the distilling chamber. A crust 4 like 9-4 is formed onthe last section of the coal and allowed to drop into the lowercontainer 14.

Suitable conduits 15 (Fig. 2) lead the fuel collected by each rotaryscraper into a leakless collecting conduit 16, which may consist of aleakless rotary feedingdevice 17 by which the fuel is discharged into' achamber which is distinct from the distilling chamber, e. g., into afurnace 18 provided with a movable grate 19 (Fig. 2).

The collecting conduit 16' may be provided with a conveyor 28 (Fig. 3)consisting for example of a worm for moving the semi-coke to a givenpoint, e. 5., into a crusher 21 (Fig. 3) of a suitable type. This conssts of two crushing drums and a dust-collector 22. The stones, slate andother impurities drop into a container 23, and the ground and purifiedsemi-coke is drawn by a stream of air into a conduit 24.

In Figure 4-, the distilling apparatus comprises two chambers 1'--lplaced side by side, these being symmetrical with reference to the axis:c-;r'. The scrapers are combined in pairs and have a common shaft 10'provided with helical paddles l1 -11". The padles ll deliver the fuelwhich they collect into a collecting chamber 16', and the paddles 11"deliver their fuel into a like chamber which is symmetrical with thechamber 16' with reference to the axis :r--:v', and is not shown in thefigure.

As above stated, each stop plate may be provided with a device forregulating the thickness of the layer of fuel upon which it acts. Such adevice consists of a pivoting tube secured to the said stop plate, i. e.a tube 25 for the plate 12 and a tube 25 for the plate 12 Said tubeserves for the circulation of a cooling fluid (26 -26 0 such as water.Each tube such as 25 is connected with piping 27; a stuffing-box 28 anda gear wheel 29 (or the like) serve to rotate the tube 25 on its axis,thus regulating the height of the lower edge 14* of the stop plate 13.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I de-- clarethat what I claim is:

1. The process of continuous low temperature destructive distillation ofcoal comprising the following steps: moving the coal from one point toanother in a substantially continuous layer, subjecting the moving layerof coal to destructive distillation thereby causing destructivedistillation and partial agglomeration of one side of said layer,supplying the heat for the distillation by circulating hot gasesobtained from the distillation of the coal through said layer from oneside thereof to the other throughout the length and width of said layerwithin a'zone between said points, and removing from the layer withinthe longitudinal limits of said zone the agglomerated and distilledcoal.

2. The process of continuous low temperature destructive distillation ofcoal comprising the following steps: moving the coal in a substantiallycontinuous layer, subjecting the moving layer of coal to destructivedistillation thereby causing destructive distillation and partialagglomeration of one side of said layer, supplying the heat for thedistillation by circulating hot gases obtained from the distillation ofthe coal through said layer from said one side to the other throughoutthe length and width of said layer by suction applied to the other sideof the layer, breaking up and removing from the layer at one pointwithin' the longitudinal limits of the layer the crust of agglomeratedand distilled coal, and subjecting to destructive distillation past saidpoint theremainder of the coal in said layer.

3. The process of continuous low temperature destructive distillation ofcoal comprising the following steps: moving the coal in a substantiallycontinuous horizontal layer, subjecting the moving layer of coal todestructive distillation, thereby causing destructive distillation andpartial agglomeration of the upper side of said layer, supplying theheat for the distillation by circulating hot gases obtained from thedistillation of the coal throughout the length and width of said layerby applying suction to the under side of the layer, and breaking up andremoving at a plurality of points within the longitudinal limits of thelayer the crust of agglomerated and destructively distilled coal fromthe layer.

4. In an apparatus for continuous treatment for the low-temperaturedistillation of coal comprising a distilling chamber, an endlessconveyor extending into said chamber, means for moving said conveyor,means for spreading a layer of coal upon said conveyor, a gate at theentrance of the distilling chamber to control the thickness of saidlayer, a substantially horizontal shaft positioned within and acrosssaid chamber above the conveyor and rotatable on its axis, paddlesmounted on said shaft and so arranged as to transport solid fuel acrossthe said conveyor, the distilling chamber having a port adjacent saidpaddles for the discharge of the distilled fuel transported by saidpaddles.

5. In an apparatus for continuous treatment for the lowtemperaturedistillation of coal comprising a distilling chamber, an endlessconveyor permeable to gases extending into said chamber, means formoving said conveyor, means for spreading a layer of coal upon saidconveyor, a gate at the entrance of the distilling chamber to controlthe thickness of said layer, means for passing gas into said chamber andfrom said chamber through said conveyor, a substantially horizontalshaft positioned within and across said chamber above the conveyor androtatable on its axis, paddles mounted on the said shaft in the form ofa helix and adapted to transport solid fuel across said conveyor, thedistilling chamber having a lateral port adjacent the said paddles ofthe shaft for the discharge of the transported solid fuel, and a stopwithin said chamber on the opposite side of said shaft from said gateand parallel with said shaft but terminating above the conveyor.

6. In an apparatus for continuous treatment for the low-temperaturedistillation of coal comprising a distilling chamber, an endlessconveyor permeable to gases extending into said chamber, means formoving said conveyor means for spreading a layer of coal upon saidconveyor, a gate at the entrance of the distilling chamber to controlthe thickness of said layer, means for sucking gaseous products intosaid chamber and from said chamber through said conveyor, substantiallyhorizontal shafts positioned at a plurality of points within and acrosssaid chamber, above the conveyor and rotatable on their axes, paddlesmounted on each shaft in the form of a helix and adapted to transportsolid fuel across the said conveyor, the distilling chamber having aport adjacent the said paddles of each shaft for the dischage of thesaid solid fuel, a stop within said chamber on the opposite side of saidshaft from said gate and parallel with each shaft and terminating abovethe conveyor, and means for adjusting said stops with respect to saidconveyor.

7. In an apparatus for continuous treatment for the low-temperaturedistillation of coal comprising a distilling chamber, an endlessconveyor permeable to gases extending into said chamber, means formoving said conveyor means for spreading a layer of coal upon saidconveyor, a gate at the entrance of the distilling chamber to controlthe thickness of said layer, means for sucking gaseous products intosaid chamber and from said chamber through said conveyor, asubstantially horizontal shaft positioned within and across the chamberabove the conveyor and rotatable on its axis, paddles mounted on saidshaft in the form of a helix and adapted to transport solid fuel acrosssaid conveyor, the distilling chamber having a port adjacent saidpaddles for the discharge of the solid fuel, a stop within said chamberon the opposite side of said shaft from said gate and parallel with saidshaft and 1 terminating above the conveyor, 21 pivoting shaft fixed tothe said stop, and controlling means arranged on the said shaft foradjusting the height of the lower part of said stop with respect to saidconveyor.

ALFRED JEAN ANDRE HERENG.

